The Federal Motor Carrier Safety Administration (FMCSA) is issuing a safety advisory to provide notice and information to owners and operators of commercial motor vehicles (CMVs) concerning incidents that have occurred relating to the possession and use of battery-powered portable electronic smoking devices [e.g., e-cigarettes, e-cigs, e-cigars, e-pipes, e-hookahs, personal vaporizers, electronic nicotine delivery systems] and the transportation safety risks associated with the use of these devices. The use of battery-powered portable electronic smoking devices has resulted in incidents including explosions, serious personal injuries, and fires. The explosions regularly involved the ejection of a burning battery case or other components from the device which subsequently ignited nearby flammable or combustible materials. The Federal Hazardous Materials Regulations and Federal Motor Carrier Safety Regulations do not specifically address the potential safety risks posed by battery-powered portable electronic smoking devices. However, motor carriers and drivers should be cognizant of the risks associated with these devices and exercise good judgment and appropriate discretion in their possession, storage, and charging or use on, around, or while operating a CMV, and adhere to the smoking prohibitions on, near, or when loading and unloading a motor vehicle transporting hazardous materials in accordance with 49 CFR 177.834(c) and 397.13.